A woman in Belgium is the first in the world to give birth to a baby using transplanted ovarian tissue frozen when she was still a child, doctors say.
The 27-year-old had an ovary removed at age 13, just before she began invasive treatment for sickle cell anaemia.
Her remaining ovary failed following the treatment, meaning she would have been unlikely to conceive without the transplant.
Experts hope that this procedure could eventually help other young patients.
The woman gave birth to a healthy boy in November 2014, and details of the case were published on Wednesday in the journal Human Reproduction.
Bone marrow transplant
The woman, who has asked to remain anonymous, was diagnosed with sickle cell anaemia at the age of five.
She emigrated from the Republic of Congo to Belgium where doctors decided her disease was so severe that she needed a bone marrow transplant using her brother’s matching tissue.
But before they could begin the bone marrow transplant, they needed to give her chemotherapy to disable her immune system and stop it from rejecting the foreign tissue.
Chemotherapy can destroy the ovarian function, so they removed her right ovary and froze tissue fragments. At that time, she was showing signs of puberty, but had not yet started her periods. Her remaining ovary failed at 15.
Ten years later, she decided she wanted to have a baby, so doctors grafted four of her thawed ovarian fragments onto her remaining ovary and 11 fragments onto other sites in her body.
The patient started menstruating spontaneously five months later, and became pregnant naturally at the age of 27.